Sgt of Arms

[Sticks]

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Isn't buying piece-by-piece usually the most expensive way to get one??

Sometimes. It all depends on how good your shopping around skills are. Used to be that you could not build an upper for less than buying one outright, especially if you did not have the tools (clam shell, reaction rod, barrel clamp, torque wrench, barrel nut wrench...). Never mind the uppity people that looked down on "Franken Guns" (fact has not changed that resale value on them is a joke). The fanboys have calmed down and accepted that a Mutt can shoot and function as good or better than a Colt, Daniel Defense, Noveske and so on.

I have a Mk12 clone (real Compass Lake barrel though from Centurion Arms) that I assembled, without facing the Vltor Upper, or bedding the barrel extension or gas block. It shoots sub MOA as it sits. It needs to be torn down, and accurized. I have gas leaks around the gas block (need to put an adjustable on it anyhow) and a new muzzle device installed for the suppressor that I may have sometime next fall.

The upside to assembling from parts is you get exactly the parts you want, rather than swapping out parts after your complete shows up. No wasted money in parts sitting in the box with the 15 other pistol holsters you don't use anymore.

Just remember, all the accuracy is in the upper. You can have a complete sh** lower, so long as the trigger is halfway decent, and falls every time you squeeze the trigger, you won't have any issues.